Gold tegus are a form of Colombians. If you see black and gold, gold, or Colombian, it's the same type of tegu.

Too bad Varnyard (tegutalk) is sold out of Argentine B/W for the season. I have two of his tegus and I think he has the best. Prices vary...depends on what people want to sell them for and what people want to pay, just like snakes. You can look in the Classifieds here and get an idea. I'd say the average price for a hatchling tegu is about $100, but you'll find some that are less, and some a little more. Adults will vary from $150-$300, depending on size and quality.

I think it would be prudent for a beginner to learn the difference between Colombians and Argentines so that you can be certain you know what you're getting. I saw a tegu on my local Craig's List where someone's mom was selling the lizard and supplies for what seemed like the price of a Argentine. But the pic was clearly a Colombian. There is a thread below started by Flavia that shows the difference, but you can learn by seeing pics on the Internet as well.